Quarterly report pursuant to Section 13 or 15(d)

Property And Equipment (Narrative) (Details)

v3.4.0.3
Property And Equipment (Narrative) (Details) - USD ($)
3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Dec. 31, 2015
Property, Plant and Equipment [Line Items]      
Impairment of oil and gas properties $ 218,991,000 $ 0  
Cumulative capitalization of general and administrative costs incurred and capitalized to the full cost pool 107,700,000    
Capitalized general and administrative costs 7,100,000 $ 7,200,000  
Capitalized costs of oil and natural gas properties excluded from amortization $ 1,782,295,000   $ 1,817,701,000
Minimum      
Property, Plant and Equipment [Line Items]      
Expected number of years amortization will commence 3 years    
Maximum      
Property, Plant and Equipment [Line Items]      
Expected number of years amortization will commence 5 years